B737 FLC HAS SLIDING COCKPIT SIDE WINDOW OPEN DURING TKOF ROLL. TKOF ABORTED.

Narrative

TKOF WAS ABORTED AT 115 KTS; BECAUSE THE FO'S WINDOW OPENED ABRUPTLY; ALMOST VIOLENTLY. IT SLID BACK ON THE RAIL TO THE FULLY OPENED POS; AND THE MOVEMENT RIPPED THE FO'S HEADSET OFF OF HIS HEAD. I INITIATED THE ABORT AT 115 KTS. THE ACFT WEIGHED ABOUT 158000 LBS. WE WERE DOING A BLEEDS OFF; RWY 26R TKOF. WX WAS VFR; RWY WAS DRY. I RELEASED THE AUTO BRAKES ALMOST IMMEDIATELY AND USED FULL REVERSER ON BOTH ENGS. WE TAXIED TO THE DEP END AND CALCULATED BRAKE COOL DOWN PERIOD. THE RESULT WAS A WAG AT BEST; SINCE REJECTED TKOF AUTOBRAKES WERE USED FOR ONLY A FEW SECONDS AND THEN LIGHT MANUAL BRAKING THEREAFTER. AFTER SITTING FOR 30 MINS WITHOUT SETTING THE PARKING BRAKES; I STARTED TO MOVE THE ACFT. AT THIS POINT; THERE WAS A VERY DEFINITIVE GRABBING OR STICKING OF THE BRAKES THAT MADE THE FO AND I BOTH VERY UNCOMFORTABLE ABOUT CONTINUING. WE THEN TAXIED BACK TO THE GATE AND HAD THE BRAKES AND TIRES CHKED BY MAINT. THE BRAKES WERE HOT AND THE TIRE PRESSURE WAS HIGH. AFTER ABOUT AN ADDITIONAL HR OF COOLING; WE DEPARTED WITHOUT INCIDENT. AS FAR AS THE WINDOW GOES; I WATCHED THE FO CHK THE WINDOW CLOSED DURING THE PREFLT CHKS; AND IT APPEARED CLOSED AND LOCKED AS MUCH AS ALL THE OTHER WINDOWS I'VE WATCHED FO'S CLOSE. A MECH CHKED IT WHILE THE BRAKES WERE COOLING; AND FOUND NOTHING WRONG. BEFORE ABORTING; I DID CONSIDER CONTINUING AND TRYING TO CLOSE THE WINDOW IN THE AIR; BUT THE NOISE AND CONFUSION LEVEL WAS SO HIGH THAT ABORTING SEEMED THE PRUDENT OPTION.